CD209 Protein

Quality Statement:
Human Dendritic Cell-specific ICAM-3 Grabbing Non-integrin (DC-SIGN)/CD209 is a member of the C-type lectin family. The canonical DC-SIGN/CD209 isoform is a 46 kDa, 404 amino acid (aa) type II transmembrane protein. The extracellular region contains a Ca2+-dependent carbohydrate-binding lectin domain. Multiple human DC-SIGN/CD209 splice forms exist, generating both membrane-bound and soluble forms. Pathogen-recognition receptor expressed on the surface of immature dendritic cells (DCs) and involved in initiation of primary immune response. Thought to mediate the endocytosis of pathogens which are subsequently degraded in lysosomal compartments. The receptor returns to the cell membrane surface and the pathogen-derived antigens are presented to resting T-cells via MHC class II proteins to initiate the adaptive immune response. On DCs it is a high affinity receptor for ICAM2 and ICAM3 by binding to mannose-like carbohydrates. May act as a DC rolling receptor that mediates transendothelial migration of DC presursors from blood to tissues by binding endothelial ICAM2. Seems to regulate DC-induced T-cell proliferation by binding to ICAM3 on T-cells in the immunological synapse formed between DC and T-cells.

Reference:
1.Liu, W. et al. (2004) J. Biol. Chem. 279:18748.2.Curtis, B.M. et al. (1992) Proc. Natl. Acad. Sci. USA 89:8356.3.Mummidi, S. et al. (2001) J. Biol. Chem. 276:33196.